Global Door Controls CPS4040-USP-3 Cps Series Spring Hinge Imperial Usa's Cps Series 4 x 4 inch Full Mortise Spring Steel Based Hinge - Set of 3 4" x 4" inch square spring hinge Full mortise commercial spring hinge Packed with wood and machine screws for easy installation UL listed R19063 for "A" label fire doors Comes primed for paint (USP finish)